>It’s strange how one eyebrow (in the back) got completely obliterated while the other looks completely fine, and it’s even stranger how the texture of the collar (in front) is basically perfect on the left where it’s unobstructed but basically destroyed on the right where some hair escaping from the braids was in front of it

As I mentioned in another comment, even this isn't strange when you consider that the areas where detail is lost are in shadow (compared to the similar areas where more detail is preserved). That means less contrast, which means more detail lost to denoising.